title: Comparison of mercury concentrations in landlocked, resident, and sea-run fish (Salvelinus spp.) from Nunavut, Canada.
abstract: Mercury concentrations ([Hg]) in Arctic food fish often exceed guidelines for human subsistence consumption. Previous research on two food fish species, Arctic char (Salvelinus alpinus) and lake trout (Salvelinus namaycush), indicates that anadromous fish have lower [Hg] than nonanadromous fish, but there have been no intraregional comparisons. Also, no comparisons of [Hg] among anadromous (sea-run), resident (marine access but do not migrate), and landlocked (no marine access) life history types of Arctic char and lake trout have been published. Using intraregional data from 10 lakes in the West Kitikmeot area of Nunavut, Canada, we found that [Hg] varied significantly among species and life history types. Differences among species-life history types were best explained by age-at-size and C:N ratios (indicator of lipid); [Hg] was significantly and negatively related to both. At a standardized fork length of 500 mm, lake trout had significantly higher [Hg] (mean 0.17 µg/g wet wt) than Arctic char (0.09 µg/g). Anadromous and resident Arctic char had significantly lower [Hg] (each 0.04 µg/g) than landlocked Arctic char (0.19 µg/g). Anadromous lake trout had significantly lower [Hg] (0.12 µg/g) than resident lake trout (0.18 µg/g), but no significant difference in [Hg] was seen between landlocked lake trout (0.21 µg/g) and other life history types. Our results are relevant to human health assessments and consumption guidance and will inform models of Hg accumulation in Arctic fish.
authors.affiliation: Canadian Rivers Institute and Biology Department, University of New Brunswick, Saint John, New Brunswick, Canada. heidikswanson@yahoo.ca
authors.forename: Heidi
authors.initials: H
authors.lastname: Swanson
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Gantner
authors.forename: Karen A
authors.initials: KA
authors.lastname: Kidd
authors.forename: D C G
authors.initials: DC
authors.lastname: Muir
authors.forename: James D
authors.initials: JD
authors.lastname: Reist
mesh_terms: D025041:Animal Migration; D000818:Animals; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D004032:Diet / Q000706:statistics & numerical data; D004781:Environmental Exposure / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D005618:Fresh Water / Q000737:chemistry; D006801:Humans; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D020957:Nunavut; D017747:Seafood / Q000706:statistics & numerical data; D012623:Seawater / Q000737:chemistry; D014337:Trout / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D008628:Mercury; D000077194:Chlorophyll A